Disclosed in Japanese Patent Application Laid-Open No. 2009-257891 (hereafter referred to as Patent Literature 1) is a linear encoder including: a scale which is provided with two tracks (an ABS pattern and an INC pattern); and a detection head which is moved relative to the scale, the linear encoder having position detection circuits that are capable of outputting respective pieces of position information on the two tracks. Such a linear encoder is configured such that in order to increase the reliability, the same positions in the measurement axis direction on the plurality of tracks can be detected by the position detection circuits and then the resulting positions are checked against each other. That is, such a linear encoder is configured such that even when the detection head is moved relative to the scale in the measurement axis direction, the same position in the measurement axis direction can be detected on the respective tracks if the position detection times on the two tracks coincide with each other.